CN114276560B - Concentration method of beta-chitin nanofiber suspension and self-supporting material - Google Patents

Abstract

The invention discloses a concentration method of a beta-chitin nanofiber suspension and a self-supporting material, which comprise the steps of separating and purifying beta-chitin from squid cartilage; dispersing beta-chitin in water, and carrying out ultrasonic crushing treatment to obtain beta-chitin nanofiber suspension; adjusting the pH value range of the beta-chitin nanofiber suspension to 3-10, and adding polyphenol substances to obtain a polyphenol modified beta-chitin nanofiber suspension; centrifuging the polyphenol modified beta-chitin nanofiber suspension, and collecting precipitate to obtain concentrated beta-chitin nanofiber. According to the technical scheme, the beta-chitin is extracted from squid cartilage to prepare the beta-chitin nanofiber suspension, and polyphenol modification is carried out, so that the effect of shielding hydrogen bonds and electrostatic repulsion between beta-chitin nanofibers can be achieved, and efficient concentration of the beta-chitin nanofiber suspension is realized.

Description

A kind of concentration method of β-chitin nanofiber suspension and self-supporting material

Technical field

The invention relates to the field of biological material preparation, and in particular to a concentration method of β-chitin nanofiber suspension and a self-supporting material.

Background technique

Chitin is the most abundant aminopolysaccharide on Earth and is found primarily in the exoskeletons of arthropods, the bone marrow of molluscs, and the cell walls of fungi. Chitin and its derivatives have good biocompatibility, biodegradability and unique biological activities, which have attracted widespread attention in the field of biomedical materials. However, due to the strong intermolecular and intramolecular hydrogen bonding interactions of chitin, it is difficult to dissolve in general solvents, which greatly limits the further application of chitin.

Chitin nanofiber is a natural biomass fiber extracted from chitin. It not only inherits the inherent characteristics of chitin such as biocompatibility, antibacterial activity and wound healing effect, but also has ultra-high specific surface area, high length and long life. Diameter ratio, longitudinal modulus and many other properties have potential application value in biomedical, cosmetics and other fields. Currently commonly used chitin nanofibers are mainly derived from shrimp and crab shells, and their crystalline form is α-form. However, research on β-form chitin nanofibers derived from squid cartilage is limited. Squid cartilage is a fishery waste with a chitin content of about 20%. It is a natural renewable resource. Purified β-chitin can be obtained by deproteinizing and removing inorganic salts with alkaline solutions and acid solutions, and then through β-chitin nanofibers can be obtained by mechanical crushing.

The α-crystalline form is composed of two anti-parallel molecular chains, and there are both intermolecular and intramolecular hydrogen bonds, so it has poor swelling performance in water. The β-crystalline form is composed of two parallel molecular chains, with weak intermolecular hydrogen bonds and stronger liquid absorption properties. β-chitin nanofibers have a higher aspect ratio than α-chitin nanofibers, and a suspension with a concentration of 0.2% can form an entangled three-dimensional network structure, showing the properties of a gel. In addition, the β-chitin in squid cartilage has higher purity and less heavy metal content. These advantages make β-chitin nanofibers a more potential biomaterial, which can be prepared into gels or scaffolds and used in wound dressings, stem cell scaffolds and other fields.

However, β-chitin nanofiber suspension has defects such as low solid content and poor mechanical properties due to the large hydrogen bond interaction and electrostatic repulsion, making it difficult to prepare a self-supporting hydrogel or scaffold material. Further concentration enables the preparation of high-strength scaffolds. At present, suction filtration is often used for concentration, but this process takes a long time, can only form flake gel, and has poor uniformity.

Contents of the invention

The main purpose of the present invention is to propose a concentration method of β-chitin nanofiber suspension and a self-supporting material, aiming to shield the hydrogen bonding and electrostatic repulsion between β-chitin nanofibers and realize β-chitin Efficient concentration of nanofiber suspensions.

In order to achieve the above object, the present invention proposes a method for concentrating β-chitin nanofiber suspension. The concentration method of β-chitin nanofiber suspension includes: separating and purifying β-chitin from squid cartilage. ;

Disperse β-chitin in water and conduct ultrasonic pulverization to obtain β-chitin nanofiber suspension;

Adjust the pH value of the β-chitin nanofiber suspension to a range of 3 to 10, and add polyphenols to obtain a polyphenol-modified β-chitin nanofiber suspension;

The polyphenol-modified β-chitin nanofiber suspension is centrifuged, and the precipitate is collected to obtain concentrated β-chitin nanofibers.

Optionally, in the step of dispersing β-chitin in water and ultrasonic pulverizing to obtain the β-chitin nanofiber suspension, the ultrasonic pulverizing time is 12 to 14 minutes.

Optionally, in the step of adjusting the pH value of the β-chitin nanofiber suspension to 3 to 10, adding polyphenols to obtain a polyphenol-modified β-chitin nanofiber suspension, polyphenols are added. After removing the phenolic substances, stir for 6 to 48 hours to obtain a polyphenol-modified β-chitin nanofiber suspension.

Optionally, in the step of adjusting the pH value of the β-chitin nanofiber suspension to a range of 3 to 10, adding polyphenols to obtain a polyphenol-modified β-chitin nanofiber suspension, β- The mass ratio of chitin nanofibers to polyphenols is 1: (0.5-10).

Optionally, the concentration of the β-chitin nanofiber suspension is 0.5 mg/ml to 2 mg/ml.

Optionally, the polyphenols include any one of catechol, 3,4-dihydroxyphenylpropionic acid, caffeic acid, dopamine, tannic acid, ellagic acid and quercetin.

Optionally, the steps of isolating purified β-chitin from squid cartilage include:

Place the squid cartilage in a sodium hydroxide solution, heat it in an environment of 65°C to 75°C for 25 to 35 minutes, and then wash it with deionized water to obtain a neutral mixture;

The mixture was soaked in a hydrochloric acid solution, left at room temperature, and then washed with deionized water until neutral to obtain purified β-chitin.

Optionally, the step of centrifuging the polyphenol-modified β-chitin nanofiber suspension and collecting the precipitate to obtain concentrated β-chitin nanofibers includes:

After centrifuging the polyphenol-modified β-chitin nanofiber suspension at 6000-10000 rpm for 8-12 minutes, remove the upper liquid to obtain the first mixture;

Add deionized water to the first mixture for cleaning, and remove the upper liquid after cleaning to obtain a second mixture;

The second mixture is centrifuged at 6000-10000 rpm for 8-12 minutes, and the precipitate is collected to obtain concentrated β-chitin nanofibers.

Optionally, before the step of placing the squid cartilage in a sodium hydroxide solution, heating it in an environment of 65°C to 75°C for 25 to 35 minutes, and then washing it with deionized water to obtain a neutral mixture, it also includes:

Remove residual impurities on the surface of the squid cartilage, cut the squid cartilage into small sections of about 2 cm to 3 cm, and dry them in an environment of 30°C to 50°C for 12 hours.

The present invention also provides a self-supporting material, which includes concentrated β-chitin nanofibers prepared by the above-mentioned concentration method of β-chitin nanofiber suspension.

The invention provides a method for concentrating the β-chitin nanofiber suspension. The invention uses squid cartilage as raw material, separates and purifies β-chitin from the squid cartilage, prepares the β-chitin nanofiber suspension, and then uses multiple Modification of its surface by phenolic substances can shield the hydrogen bonds and electrostatic repulsion between β-chitin nanofibers and achieve efficient concentration of β-chitin nanofiber suspension. The concentrated solution can be further prepared into Self-supporting hydrogel or scaffold materials can be used in areas such as wound dressings or stem cell culture. It solves the shortcomings in the existing technology that β-chitin nanofibers have low solid content and are difficult to directly utilize, and expands the application of such biomass-derived materials in the biomedical field.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only For some embodiments of the present invention, those of ordinary skill in the art can also obtain other related drawings based on these drawings without exerting creative efforts.

Figure 1 is a flow chart of an embodiment of a method for concentrating β-chitin nanofiber suspension provided by the present invention;

Figure 2 shows β-chitin nanofibers modified and concentrated with tannic acid in Example 1 of the present invention;

Figure 3 shows the viscosity test results of β-chitin nanofiber suspension before and after tannic acid modification and concentration in Example 2 of the present invention;

Figure 4 is a physical diagram of the β-chitin nanofiber scaffold modified by dopamine hydrochloride in Example 5 of the present invention.

The realization of the purpose, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings.

Detailed ways

In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of the embodiments.

It should be noted that if specific conditions are not specified in the examples, the conditions should be carried out in accordance with conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not indicated, they are all conventional products that can be purchased commercially. In addition, the meaning of "and/or" appearing in the entire text includes three parallel solutions. Taking "A and/or B" as an example, it includes solution A, or solution B, or a solution that satisfies both A and B at the same time. In addition, the technical solutions in the various embodiments can be combined with each other, but it must be based on what a person of ordinary skill in the art can implement. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that such a combination of technical solutions does not exist. , nor within the protection scope required by the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

Due to the large hydrogen bond interaction and electrostatic repulsion, β-chitin nanofiber suspension has shortcomings such as low solid content and poor mechanical properties. It is difficult to prepare a self-supporting hydrogel or scaffold material and requires further concentration. Achieve the preparation of high-strength scaffolds. At present, suction filtration is often used for concentration, but this process takes a long time, can only form flake gel, and has poor uniformity. In view of this, the present invention proposes a method for concentrating β-chitin nanofiber suspension, aiming to shield the hydrogen bonding and electrostatic repulsion between β-chitin nanofibers and realize the concentration of β-chitin nanofiber suspension. Efficient concentration.

The present invention proposes a method for concentrating β-chitin nanofiber suspension. The method for concentrating β-chitin nanofiber suspension includes:

Step S10, isolate and purify β-chitin from squid cartilage;

In this embodiment, the squid cartilage is a kind of fishery waste and is renewable. Using squid cartilage to extract β-chitin can increase its added value and expand its application in the biomedical field. Further, the steps of isolating and purifying β-chitin from squid cartilage include:

Step S11: Remove residual impurities on the surface of the squid cartilage, cut the squid cartilage into small sections of about 2 cm to 3 cm, and dry them in an environment of 30°C to 50°C for 12 hours.

In this embodiment, the squid cartilage is cut into small sections of 2 cm to 3 cm to facilitate subsequent reactions and speed up the reaction. The temperature of the drying process is preferably 40°C.

Step S12: Place the squid cartilage in a sodium hydroxide solution, heat it in an environment of 65°C to 75°C for 25 to 35 minutes, and then wash it with deionized water to obtain a neutral mixture;

In this embodiment, the concentration of the sodium hydroxide solution is 1 mol/L. It is preferably heated at a temperature of 70° C. for 30 minutes and then washed with deionized water. This step is to deproteinize the squid cartilage.

Step S13: Soak the mixture in hydrochloric acid solution, place it at room temperature, and then wash it with deionized water until it becomes neutral, to obtain purified β-chitin.

In this embodiment, the concentration of the hydrochloric acid solution is 0.6 mol/L. After leaving it at room temperature for 60 minutes, it is washed with deionized water until it becomes neutral. This step is to remove inorganic salts from the mixture. After the step of obtaining purified β-chitin, it also includes:

Step S20: Disperse β-chitin in water and conduct ultrasonic crushing to obtain β-chitin nanofiber suspension;

In this embodiment, β-chitin nanofibers have a high aspect ratio, and a suspension with a concentration of 0.2% can form an entangled three-dimensional network structure, exhibiting gel properties. It should be noted that the ultrasonic grinding treatment time is 12 to 14 minutes, preferably 12 minutes.

Because β-chitin nanofiber suspension has defects such as low solid content and poor mechanical properties due to large hydrogen bond interactions and electrostatic repulsion, polyphenols are used to modify its surface to provide shielding The role of hydrogen bonding and electrostatic repulsion between β-chitin nanofibers. The specific method of using polyphenols for modification is as follows:

Step S30: Adjust the pH value of the β-chitin nanofiber suspension to a range of 3 to 10, and add polyphenols to obtain a polyphenol-modified β-chitin nanofiber suspension;

In this embodiment, the mass of the polyphenols is 0.2-1g, and the polyphenols include but are not limited to catechol, 3,4-dihydroxyphenylpropionic acid, caffeic acid, dopamine, Tannic acid, ellagic acid and quercetin, the mass ratio of the β-chitin nanofibers to polyphenols is 1: (0.5-10). It is worth noting that in step S30, after adding polyphenols, the polyphenol-modified β-chitin nanofiber suspension is stirred. The stirring time is 6-48 h, and the stirring method is preferably It is magnetic stirring. The magnetic stirring method can not only mix the reactants evenly and make the temperature uniform, but also speed up the reaction speed or evaporation speed, saving time. Further, after step S30, it also includes:

Step S40: Centrifuge the polyphenol-modified β-chitin nanofiber suspension, and collect the precipitate to obtain concentrated β-chitin nanofibers.

Specifically, the step S40 includes:

Step S41: After centrifuging the polyphenol-modified β-chitin nanofiber suspension at 6000-10000 rpm for 8-12 minutes, remove the upper liquid to obtain the first mixture;

In this embodiment, the centrifugation time in step S41 is preferably 10 minutes.

Step S42: Add deionized water to the first mixture for cleaning, and remove the upper liquid after cleaning to obtain a second mixture;

In this embodiment, deionized water is added to the first mixture for cleaning, and the step of removing the upper liquid after cleaning is repeated three times to obtain a purer second mixture.

Step S43: Centrifuge the second mixture at 6000-10000 rpm for 8-12 minutes, and collect the precipitate to obtain concentrated β-chitin nanofibers.

In this embodiment, the centrifugation time in step S43 is preferably 10 minutes.

The present invention also provides a self-supporting material, which includes concentrated β-chitin nanofibers prepared by the concentration method of β-chitin nanofiber suspension as described above. The concentrated β-chitin nanofibers can be prepared into self-supporting materials through simple freeze-drying, salting out, chemical cross-linking, etc. The self-supporting materials include self-supporting gels or porous scaffold materials, and are modified with polyphenols. The hydrophilicity and biological activity of the self-supporting material can be effectively improved.

The technical solution of the present invention will be further described in detail below with reference to specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

Example 1

(1) Isolate and purify β-chitin from squid cartilage;

(2) Disperse 0.2g of purified β-chitin in 100 mL of deionized water and treat it with an ultrasonic grinder for 12 minutes to obtain a β-chitin nanofiber suspension with a concentration of 2 mg/ml.

(3) Take 100 mL of chitin nanofibers, adjust the pH to 8 with 1 mol/L NaOH solution, add 0.4 g of tannic acid, and magnetically stir at room temperature for 6 hours to obtain tannic acid-modified β-chitin nanofiber suspension. liquid.

(4) Centrifuge the obtained product at 6000 rpm for 10 minutes, remove the supernatant, and wash it 3 times with deionized water. Centrifuge at 8000 rpm for 10 minutes to collect the precipitate to obtain concentrated β-chitin nanofibers, which are weighed. The solid content measured by the method is 1.0%.

Example 2

(1) Isolate and purify β-chitin from squid cartilage;

(2) Disperse 0.2g of purified β-chitin in 100 mL of deionized water and treat it with an ultrasonic grinder for 12 minutes to obtain a β-chitin nanofiber suspension with a concentration of 2 mg/ml.

(3) Take 100 mL of chitin nanofibers, adjust the pH to 8 with 1 mol/L NaOH solution, add 0.6 g of tannic acid, and magnetically stir at room temperature for 6 hours to obtain tannic acid-modified β-chitin nanofiber suspension. liquid.

(4) Centrifuge the obtained product at 8,000 rpm for 10 minutes, remove the supernatant, and wash it three times with deionized water. Centrifuge at 10,000 rpm for 10 minutes to collect the precipitate to obtain concentrated β-chitin nanofibers, which are weighed. The solid content measured by the method is 1.5%.

Example 3

(1) Isolate and purify β-chitin from squid cartilage;

(2) Disperse 0.2g of purified β-chitin in 100 mL of deionized water and treat it with an ultrasonic grinder for 12 minutes to obtain a β-chitin nanofiber suspension with a concentration of 2 mg/ml.

(3) Take 100 mL of chitin nanofibers, adjust the pH to 8.5 with 1 mol/L NaOH solution, add 0.4 g of catechol, and stir magnetically at room temperature for 24 hours to obtain catechol-modified β-chitin nanofibers. Fiber suspension.

(4) Centrifuge the obtained product at 8,000 rpm for 10 minutes, remove the supernatant, and wash it three times with deionized water. Centrifuge at 10,000 rpm for 10 minutes to collect the precipitate to obtain concentrated β-chitin nanofibers, which are weighed. The solid content measured by the method is 0.9%.

Example 4

(1) Isolate and purify β-chitin from squid cartilage;

(2) Disperse 0.2g of purified β-chitin in 100 mL of deionized water and treat it with an ultrasonic grinder for 12 minutes to obtain a β-chitin nanofiber suspension with a concentration of 2 mg/ml.

(3) Take 100mL of chitin nanofibers, adjust the pH to 4 with 1mol/L HCL solution, add 0.2g of 3,4-dihydroxyphenylpropionic acid and 0.16g of 1-(3-dimethylaminopropyl)-3 -Ethylcarbodiimide, stir magnetically at room temperature for 12 hours, and obtain a 3,4-dihydroxyphenylpropionic acid-modified β-chitin nanofiber suspension.

(4) Centrifuge the obtained product at 6000 rpm for 10 minutes, remove the supernatant, and wash it 3 times with deionized water. Centrifuge at 8000 rpm for 10 minutes to collect the precipitate to obtain concentrated β-chitin nanofibers, which are weighed. The solid content measured by the method is 1.6%.

Example 5

(1) Isolate and purify β-chitin from squid cartilage;

(2) Disperse 0.2g of purified β-chitin in 100 mL of deionized water and treat it with an ultrasonic grinder for 12 minutes to obtain a β-chitin nanofiber suspension with a concentration of 2 mg/ml.

(3) Take 100 mL of chitin nanofibers, adjust the pH to 8.5 with 1 mol/L NaOH solution, add 0.6 g of dopamine hydrochloride, and magnetically stir at room temperature for 12 hours to obtain a dopamine-modified β-chitin nanofiber suspension.

(4) Centrifuge the obtained product at 8,000 rpm for 10 minutes, remove the supernatant, and wash it three times with deionized water. Centrifuge at 10,000 rpm for 10 minutes to collect the precipitate to obtain concentrated β-chitin nanofibers, which are weighed. The solid content measured by the method is 0.8%.

(5) Take 1.5 mL of concentrated β-chitin nanofibers and place it in a 24-well plate, freeze it at -20°C for 24 hours, and then freeze-dry it for 48 hours to obtain a self-supporting chitin nanofiber porous scaffold material (as shown in the figure) shown in 4).

Example 6

(1) Isolate and purify β-chitin from squid cartilage;

(2) Disperse 0.2g of purified β-chitin in 100 mL of deionized water, and treat it with an ultrasonic grinder for 14 minutes to obtain a β-chitin nanofiber suspension with a concentration of 2 mg/ml.

(3) Take 100 mL of chitin nanofibers, adjust the pH to 10 with 1 mol/L NaOH solution, add 0.1 g of caffeic acid, and magnetically stir at room temperature for 6 hours to obtain a suspension of caffeic acid-modified β-chitin nanofibers.

(4) Centrifuge the obtained product at 10,000 rpm for 8 minutes, remove the supernatant, and wash it three times with deionized water. Centrifuge at 10,000 rpm for 8 minutes to collect the precipitate to obtain concentrated β-chitin nanofibers.

Example 7

(1) Isolate and purify β-chitin from squid cartilage;

(2) Disperse 0.2g of purified β-chitin in 300 mL of deionized water, and treat it with an ultrasonic grinder for 13 minutes to obtain a β-chitin nanofiber suspension with a concentration of 0.5 mg/ml.

(3) Take 100 mL of chitin nanofibers, adjust the pH to 3 with 1 mol/L HCL solution, add 2 g of ellagic acid, and magnetically stir at room temperature for 48 hours to obtain an ellagic acid-modified β-chitin nanofiber suspension. .

(4) Centrifuge the obtained product at 60,000 rpm for 12 minutes, remove the supernatant, wash it three times with deionized water, and centrifuge at 10,000 rpm for 12 minutes to collect the precipitate to obtain concentrated β-chitin nanofibers. Result analysis:

The β-chitin nanofiber suspension obtained in Example 2 before and after tannic acid modification and concentration was subjected to a viscosity test using a rotational rheometer in continuous scanning mode. The results are shown in Figure 3. It can be found that both have shear thinning. performance, and the viscosity of the suspension increased significantly after modification and concentration, indicating that polyphenol modification can effectively shield the hydrogen bond interaction and electrostatic repulsion between β-chitin nanofibers and achieve enrichment of β-chitin nanofibers. The set can provide a basis for subsequent preparation of self-supporting materials.

The above are only preferred embodiments of the present invention, which do not limit the patent scope of the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the patent protection scope of the present invention.

Claims (9)

1. A method for concentrating β-chitin nanofiber suspension, which is characterized in that it includes the following steps: Isolated and purified β-chitin from squid cartilage; Disperse β-chitin in water and conduct ultrasonic pulverization to obtain β-chitin nanofiber suspension; Adjust the pH value of the β-chitin nanofiber suspension to a range of 3 to 10, and add polyphenols to obtain a polyphenol-modified β-chitin nanofiber suspension, wherein the β-chitin nanofiber and The mass ratio of polyphenols is 1: (0.5~10); The polyphenol-modified β-chitin nanofiber suspension is centrifuged, and the precipitate is collected to obtain concentrated β-chitin nanofibers. 2. The concentration method of β-chitin nanofiber suspension as claimed in claim 1, characterized in that, in the step of dispersing β-chitin in water and ultrasonic crushing to obtain β-chitin nanofiber suspension, The time of ultrasonic crushing treatment is 12 to 14 minutes. 3. The concentration method of β-chitin nanofiber suspension as claimed in claim 1, wherein the pH value range of the β-chitin nanofiber suspension is adjusted to 3 to 10, and polyphenols are added. , in the step of obtaining the polyphenol-modified β-chitin nanofiber suspension, add polyphenols and stir for 6 to 48 hours to obtain the polyphenol-modified β-chitin nanofiber suspension. 4. The concentration method of β-chitin nanofiber suspension according to claim 1, characterized in that the concentration range of the β-chitin nanofiber suspension is 0.5 mg/ml~2 mg/ml. 5. The concentration method of β-chitin nanofiber suspension as claimed in claim 1, wherein the polyphenols include catechol, 3,4-dihydroxyphenylpropionic acid, and caffeic acid. , dopamine, tannic acid, ellagic acid and any one of quercetin. 6. The concentration method of β-chitin nanofiber suspension as claimed in claim 1, wherein the step of separating and purifying β-chitin from squid cartilage includes: Place the squid cartilage in a sodium hydroxide solution, heat it in an environment of 65°C to 75°C for 25 to 35 minutes, and then wash it with deionized water to obtain a neutral mixture; The mixture was soaked in a hydrochloric acid solution, left at room temperature, and then washed with deionized water until neutral to obtain purified β-chitin. 7. The concentration method of β-chitin nanofiber suspension as claimed in claim 6, characterized in that, the polyphenol-modified β-chitin nanofiber suspension is centrifuged, and the precipitate is collected to obtain concentrated The steps for β-chitin nanofibers include: After centrifuging the polyphenol-modified β-chitin nanofiber suspension at 6000-10000 rpm for 8-12 minutes, remove the upper liquid to obtain the first mixture; Add deionized water to the first mixture for cleaning, and remove the upper liquid after cleaning to obtain a second mixture; The second mixture is centrifuged at 6000-10000 rpm for 8-12 minutes, and the precipitate is collected to obtain concentrated β-chitin nanofibers. 8. The concentration method of β-chitin nanofiber suspension as claimed in claim 6, characterized in that the squid cartilage is placed in a sodium hydroxide solution and heated for 25~75°C in an environment of 65°C~75°C. Before the step of washing with deionized water to obtain a neutral mixture after 35 minutes, it also includes: Remove residual impurities on the surface of the squid cartilage, cut the squid cartilage into small sections of about 2cm to 3cm, and dry them in an environment of 30°C to 50°C for 12 hours. 9. A self-supporting material, characterized by comprising concentrated β-chitin nanofibers prepared by the concentration method of β-chitin nanofiber suspension according to any one of claims 1 to 8.